Post-transcriptional modifications in RNAs regulate their biological behaviors and functions. N1-methyladenosine (m1A), which is dynamically regulated by writers, erasers and readers, has been found as a reversible modification in tRNA, mRNA, rRNA and long non-coding RNA (lncRNA). m1A modification has impacts on the RNA processing, structure and functions of targets. Increasing studies reveal the critical roles of m1A modification and its regulators in tumorigenesis. Due to the positive relevance between m1A and cancer development, targeting m1A modification and m1A-related regulators has been of attention. In this review, we summarized the current understanding of m1A in RNAs, covering the modulation of m1A modification in cancer biology, as well as the possibility of targeting m1A modification as a potential target for cancer diagnosis and therapy.

Our previous study indicated that intravenous vitamin C (IVC) treatment concurrent with modulated electrohyperthermia (mEHT) was safe and improved the quality of life (QoL) of non-small-cell lung cancer (NSCLC) patients. The aim of this trial was to further verify the efficacy of the above combination therapy in previously treated patients with refractory advanced (stage IIIb or IV) NSCLC. A total of 97 patients were randomized to receive IVC and mEHT plus best supportive care (BSC) (n = 49 in the active arm, receiving 1 g/kg * d IVC concurrently with mEHT, three times a week for 25 treatments in total) or BSC alone (n = 48 in the control arm). After a median follow-up of 24 months, progression-free survival (PFS) and overall survival (OS) were significantly prolonged by combination therapy compared to BSC alone (PFS: 3 months vs 1.85 months, P < 0.05; OS: 9.4 months vs 5.6 months, P < 0.05). QoL was significantly increased in the active arm despite the advanced stage of disease. The 3-month disease control rate after treatment was 42.9% in the active arm and 16.7% in the control arm (P < 0.05). Overall, IVC and mEHT may have the ability to improve the prognosis of patients with advanced NSCLC.

Circulating microRNAs (miRNAs) are promising biomarkers for cancer detection. However, multiethnic and multicentric studies of non-small-cell lung cancer (NSCLC) are lacking. We recruited 221 NSCLC patients, 161 controls and 56 benign nodules from both China and America. Initial miRNA screening was performed using the TaqMan Low Density Array followed by confirming individually by RT-qPCR in Chinese cohorts. Finally, we performed a blind trial from an American cohort to validate our findings. RT-qPCR confirmed that miR-483-5p, miR-193a-3p, miR-25, miR-214 and miR-7 were significantly elevated in patients compared to controls. The areas under the curve (AUCs) of the ROC curve of this five-serum miRNA panel were 0.976 (95% CI, 0.939-1.0; P < 0.0001) and 0.823 (95% CI, 0.75-0.896; P < 0.0001) for the two confirmation sets, respectively. In the blind trial, the panel correctly classified 95% NSCLC cases and 84% controls from the American cohort. Most importantly, the panel was capable of distinguishing NSCLC from benign nodules with an AUC of 0.979 (95% CI, 0.959-1.0) in the American cohort and allowed correct prediction of 86% and 95% stage I-II tumors in the Chinese and American cohorts, respectively. This serum miRNA panel holds the potential for diagnosing ethnically diverse NSCLC patients.

Mutations in epidermal growth factor receptor (EGFR) rendering it constitutively active is one of the major causes for metastatic non-small-cell lung cancer (NSCLC), and EGFR-targeted therapies utilizing tyrosine kinase inhibitors (TKIs) are often used clinically as the first-line treatment. But approximately half of NSCLC patients develop resistance to these therapies, where the MET proto-oncogene is amplified by EGFR through the hypoxia-inducible factor (HIF)-1α. Here we report that endothelial PAS domain-containing protein 1 (EPAS1), with 48% sequence identity to HIF-1α, specifically binds to TKI-resistant T790M EGFR, but not to wild-type EGFR, in NSCLC cell lines. Expression of EPAS1 enhances amplification of MET when simultaneously expressed with T790M EGFR but not with wild-type EGFR, and this enhancement is independent of ligand binding domain of EGFR. MET amplification requires EPAS1, since EPAS1 knock-down reduced MET levels. When NSCLC cells expressing T790M EGFR were treated with TKIs, reduced EPAS1 levels significantly enhanced the drug effect, whereas over-expression of EPAS1 increased the drug resistant effect. This EPAS1-dependent TKI-resistance was abolished by knocking-down MET, suggesting that EPAS1 does not cause TKI-resistance itself but functions to bridge EGFR and MET interactions. Our findings suggest that EPAS1 is a key factor in the EGFR-MET crosstalk in conferring TKI-resistance in NSCLC cases, and could be used as a potential therapeutic target in TKI-resistant NSCLC patients.